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[11135i]

So I'm due for a replacement on my rear tires (r18) so I go and purchase some from the lowest seller on eBay.

I really should have double checked my rear fitments before making said purchase.

So, is it possible/alright/driveable/tossable/hoonable with this on the rears or am I better off just biting the bullet and paying the return charge? My fronts are still 90% and I'm driving on the highways and hills of sunny California.

[ShocknAwe]

Get the right tire.

[Gary@TireRack]

235/40R18 will fit on rear 18X8.5" wheels with no problem.

[brocklanders]

I use that size in the rear and 225/40 up front. Although I thought you shouldn't mix two different types of tires as in one type on the front and a different on the back, maybe Gary can comment about that.

[dcaron9999]

If your total diameter rear and front are within 3%, you will be OK. Assuming this is for a 135i, I would never downsize the 245/35 rears as getting traction is already a challenge with 300ft-lbs of torque and one wheel drive (open e-diff)...

[brocklanders]

Originally Posted by dcaron9999

If your total diameter rear and front are within 3%, you will be OK. Assuming this is for a 135i, I would never downsize the 245/35 rears as getting traction is already a challenge with 300ft-lbs of torque and one wheel drive (open e-diff)...

I did because I went with zll's and according to tirerack they were 1/2" wider tread width then the 245/35 Bridgestones due to the square sidewalls. So my logic was I'm actually getting more usable contact patch in the rear while getting the front and back as close as possible without changing wheels. And I only spun out once at the autocross, but in my defense it was the second time I've ever driven a rear wheel drive car without stability control active, and in that situation I doubt the stock tires would have mattered, but I can't say that with certainty because I had never turned off dsc with the original tires.